Irrigated catheter with improved irrigation flow

Abstract

An irrigated ablation catheter provides improved distribution of irrigation fluid across its tip electrode surface resulting in improved cooling and flushing of blood and proteins from the tip region. An axially directed flow of irrigation provides improved heat transfer from the tip electrode to the irrigation fluid allowing for a cooler tip electrode and larger lesions. The irrigation fluid is introduced to the catheter with improved flow by means of a standard constant flow pump. A lumen or tube within a shaft of the catheter transfers the irrigation fluid to a proximal end of the tip electrode where it exits the catheter via a flow directing member mounted on the tip electrode. In one embodiment, the flow directing member is a thin walled tube that surrounds the proximal end of the tip electrode and directs the irrigation fluid distally along an outer surface of the tip electrode.

1. An irrigated tip catheter comprising:
 a catheter body; 
 a control handle proximal to the catheter body; 
 a deflectable section distal of the catheter body; 
 a tip electrode distal of the deflectable section, the tip electrode having an outer surface; 
 a generally tubular member positioned at least partially over the tip electrode to direct fluid to flow over at least a portion of the outer surface, wherein the tubular member is mounted over at least a portion of a proximal end of the tip electrode and a distal end of the deflectable section, the tubular member having an inner surface spaced apart from the outer surface of the tip electrode to provide at least one fluid channel for the fluid to flow over the outer surface of the tip electrode; 
 a cavity defined by the proximal end of the tip electrode, the distal end of the deflectable section, and the inner surface of the tubular member, wherein fluid entering the cavity is directed to the outer surface of the tip electrode; and 
 at least one connective tube extending through the cavity to isolate components extending between the tip electrode and the deflectable section from exposure to the fluid. 
 
     
     
       2. An irrigated tip catheter of  claim 1 , wherein the tubular member is supported away from the outer surface of the tip electrode by at least one rib to provide at least one fluid channel between the inner surface of the tubular member and the outer surface of the tip electrode. 
     
     
       3. An irrigated catheter of  claim 1 , wherein one of the at least one connective tube is notched at its distal end to protect the components extending therethrough. 
     
     
       4. An irrigated catheter of  claim 1 , wherein the outer surface of the tip electrode is texturized. 
     
     
       5. An irrigated catheter of  claim 1 , wherein fins are provided on the outer surface of the tip electrode. 
     
     
       6. An irrigated catheter of  claim 1 , wherein the tubular member covers at least a proximal edge of the tip electrode. 
     
     
       7. An irrigated catheter of  claim 1 , further comprising a temperature sensing means positioned at or near a center of the tip electrode. 
     
     
       8. An irrigated catheter of  claim 7 , wherein the temperature sensing means comprises wires whose distal ends are positioned at or near a center of a semi-spherically configured distal end of the tip electrode for omnidirectional temperature sensing. 
     
     
       9. An irrigated catheter of  claim 1 , further comprising a temperature sensing means positioned to sense temperature omnidirectionally with respect to a tissue-contacting surface of the tip electrode. 
     
     
       10. An irrigated catheter of  claim 1 , wherein the tubular member is constructed of polyetheretherketone. 
     
     
       11. An irrigated tip catheter comprising:
 a catheter body; 
 a tip electrode distal of the catheter, the tip electrode having an outer surface; 
 a flow directing member comprising a generally tubular member having an inner surface spaced apart from the outer surface of the tip electrode and a distal portion in a generally surrounding relationship with at least a proximal end of the tip electrode, the flow directing member providing at least one fluid channel to direct fluid transferred by the catheter body to flow over the outer surface of the tip electrode; 
 a cavity defined by the proximal end of the tip electrode, a distal end of the catheter body, and the inner surface of the tubular member, wherein fluid entering the cavity is directed to contact the outer surface of the tip electrode; and 
 at least one connective tube extending through the tubular member and cavity to isolate components extending into the tip electrode from exposure to the fluid. 
 
     
     
       12. An irrigated tip catheter of  claim 11 , wherein the flow directing member is configured to direct the fluid to contact at least a proximal face and a circumferential surface of the tip electrode. 
     
     
       13. An irrigated tip catheter of  claim 11 , wherein the flow directing member is configured to direct the fluid to flow in an axial direction along the outer surface of the tip electrode. 
     
     
       14. An irrigated tip catheter of  claim 11 , wherein the outer surface of the tip electrode is texturized to increase contact between the fluid and the tip electrode. 
     
     
       15. An irrigated tip catheter of  claim 11 , further comprising a deflectable section between the catheter body and the tip electrode. 
     
     
       16. An irrigated tip catheter of  claim 11 , further comprising an electromagnetic location sensor.